how God anointed Jesus of Nazareth with the Holy Spirit and with power, who went about doing good and healing all who were oppressed by the devil, for God was with Him. Acts 10:38
And there are also many other things that Jesus did, which if they were written one by one, I suppose that even the world itself could not contain the books that would be written. Amen. John 21:25
The only people where Jesus did just a few healings was in His hometown where they didn’t receive as the Messiah but saw him as they had always known Him, as the carpenters son.
When He had come to His own country, He taught them in their synagogue, so that they were astonished and said, “Where did this Man get this wisdom and these mighty works? Is this not the carpenter’s son? Is not His mother called Mary? And His brothers James, Joses, Simon, and Judas? And His sisters, are they not all with us? Where then did this Man get all these things?” So they were offended at Him.
But Jesus said to them, “A prophet is not without honor except in his own country and in his own house.” Now He did not do many mighty works there because of their unbelief. Matthew 13:54-58
So we see one of the main reasons many are not healed is their unbelief.
JLB